Presser-lifting device



Mar. 27, 1923. 1,449,771.

, F. W. MERRICK.

, PREssER LIFTING DEVICE.

FILED DEC. 2B. 1917.

Patented Mar. 27, 1923,

FRANK W. MRRICK, OF-BOSTON', MASSACHUSETTS.

rnnssER-LIFTIG iiEvIon.

Application ined December as, i917. serial iro. 209,359.

T 0 all' (whom t may concern Be it known that I, F RANK W. Mannion,

a citizen of the United States, residing at Boston, in the county of SuEolk, State of Massachusetts, have invented a certain new and useful Improvement in Presser-Lifting Devices, of which `the following is a specification, reference being had therein to the accompanying drawings. y

M improved presser-lifting devices are app icable to various kinds of machines, although shown vand described herein with reference to their employment in connection with a sewing machine. j

The said devices are an improvement in presser-lifting devices on the order of those of my prior Letters Patent No". 629,108, granted July 18, 1899, namely: of the class in which a presser-bar having a portion of its length screw-threaded has combined with vit a revoluble nut fitting the said sorewthreaded portion, and a lifter-device inter` mittiiigly actuated by a liftingactuator and which kby the rst portion of its upward movement clamps and locks the nut so as to prevent it from revolving around the screwthreaded portion of the presser-bar, 'and by the latter portion of such movement operates through the looked nut 'to raise the presser-bar and presser. y

The general object of the invention is to provide presser-lifting devices, applicable to sewing and other machines, which shall be free from disadvantages and drawbacks of'd'evices for the same purpose heretofore in use.

'Ivlieinvention provides devices capable of easy and light action, free from material liability to cause lateral pressure of theL presser-bar .within its guides o'r bearings and resulting wear of the presser-bar and guides or bearings. f

The invention involves the employment of a compound-lever lifter-device comprising a nut-locking secondary ylever-member and a primary lever-member against which the lifting actuator acts to 'actuate the. said secondary lever-member for the purpose of locking the nut from turning, and to raise the presser and associated parts and control the descent thereof; The invention involves also a particular arrangement and relationship of the said lever-members and lifting actuator by which the tendency to lateral pressure and wear is practically elimi- Dil-ted. i

The drawings show an embodiment ofthe invention applied in connection with the presser-and presser-bai' of a sewing machine.' v i Fig. l is thereof,sli`owing the said embodiment.

'Fig'. 2 is a partly sectional view of the parts that are shown in Fig. 1, looking from theright-hand side in Fig. 1. l

Figs. 3' to 11, inclusive, are views of detail parts to which reference'is made in the course ofthe following description.

The drawings show t the upright l and horizontally extending arm 2 of 'themain fixed part of a sewing machine, the head 3 at V.the vouter end of said arm, the presser-bar 4 `fitted for movement vertically in and with relation tothe said head, the presser carried bythe `presser-bar, the .presser-depressing spring @acting downwardly. upon the ltop of the presser-bar 4, and the work-support 6. t Y Y.

. At 7 is .the screw-threaded. upper portion of the presser-bar, preferably formed with a quadruple 'thread in order to vgive a ver. sharp angle of pitch. At 8 istlie nut wliic is V-mounted uponV this threaded portion vof the presser-bar, with its internal thread engaged'V with the said spiralk thread of the presser-bar.; The saidnut is shown separately in sideelevation and plan,- respectively, 'vin 3 and 4.

A carrier-member constituted by an arml 9, vshown vseparately in plan in Fig. 5, is: mounted upon the-said threaded portion of the Apresser-barbv means of lugs9a, 9a, Figs.- 1 andl, of said which the said portion of the presser-bar passes, oneof said lugs beingabove the nut 8 and arranged to make contact with the topside thereof and the other lug being besleeve 17 carried by the bearing-portion of the head 3. The lower portion of the presser-bar 4.-

l an elevation of certa-in parts of' .the said machine, 4looking at the head-end Y, i arm which have smooth holes 9b, Fig. 5, therethrough throughl works in a guide-hole or bearing made vertically through the lower portion 3a of the head 3. The screw-threaded upper portion of t-he presser-bar fits within a sleeve 9D connected with and rising from the upper lug 9a of arm 9, and is adapted to move vertically in and through the said sleeves. The sleeve 9b, in turn, is fitted to a guidebearing in the upper portion 3b of the head 3, and is adapted to move vertically in and through said guide-bearing. The sleeve is itself a bearing for the screw-threaded upper portion of the presser-bar, and in addition constitutes an elongated bearing for the arm -9 upon the presser-bar by which tendency of the arm to cramp against the presser-bar so as to interfere with the desired relative vertical movement of these two parts is obviated.

In the present embodiment of the invention, the arm 9 is slotted vertically throughout the greater portion of its length as shown in Fig. 5, and within the slot as shown in Fig. 1 is fitted a nut-locking lever 10, which is mounted upon said arm by means of a pivot 11 located at a point close to the presser-bar. Fig. 6 shows the said lever 10 in side elevation, and Fig. 7 is a plan thereof. Lever 10 is a lever of the first order. Its inner arm has its end concaved to fit the exterior of the nut. The power-arm of said lever extends outward from pivot 11. Another lever, 12, shown separately in side elevation in Fig. 8 and in plan in Fig. 9, is mounted upon arm 9 within the slot of the latter by means of a pivot 13 that is located farther away from the presser-bar than the pivot 11 of lever 10. lIhe lever 12 is a lever of the second order. It extends from its pivot 13 toward the presser-bar, and the outwardly-extending power-arm of lever 10 rests upon the top of lever 12. Lever 12 rests upon the grooved top of a lifting-actuator constituted by a rocker-arm 14, Figs. 10 and 11, fixed upon the outer end ofa rock shaft 15, Figs. 2 and 11, that is mounted in bearings (one of which is shown at 16, Fig. 2) in connection with machine-arm 2. Fig. 10 is a side elevation of rocker-arm 14, and Fig. 11 is a. plan of the said rocker-arm and the outer end of rock-shaft 15. The lower 0rtion of the lever 12 fits between the raised side-walls 14a, 14, of rocker-arm 14 while its top extends 'up between the side-walls of the arm 9. By means of the two pairs of side-walls he lever 12 is kept from sidewise displacement.

As rocker-arm 14 is rocked upwardly from its position in Figs. 1 and 2, its upward pressure, acting through lever 12 against lever 10, causes the inner arm of lever 1() -to engage with the nut 8, gripping the nut so that the latter is locked effectually from turning upon the threaded portion of the presserbar. After lever 1() brings up firmly against nut 8, the continued upward rocking movement of the rocker-arm has the effect of lifting the presser-bar and presser. The succeeding downward movement of rockerarm 14 lowers the arm 9, presser-bar, and presser, until the presser rests upon the top surface of the work, or upon the work-support, or until the arm 9 rests upon the top end of stop-sleeve 17. ln the lowering movement, the combined downward pressure of presser-depressing spring 4 acting through the nut 8, arm 9, lever 10 and lever 12, and pull of spring 16, keeps lever 12 .firmly pressed against the rocker-arm until the presser rests upon the work or work-support or the arm 9 rests upon the top end of stopsleeve 17. Until then the nut is kept locked and the presser-bar and presser under the control of the rocker-arm while the resserbar and presser are being lowered. i s soon as the presser takes bearing upon the top surface of the work or the work-support, or the arm 9 takes bearing upon the top end of the stop-sleeve 17, the pressure of the inner end of lever 1() against thenut is relaxed, so that the nut is left free to turn, whereupon the nut turns so as to permit arm 9 to adjust itself downward until it touches the top of stop-sleeve 17, or the presser to adjust itself downward until it bears upon the surface of the work or of the work-support.

The extension of the rocker-arm 14 i11- ward from the rock-shaft 15 toward the presser-bar, the action of the rocker-arm against the under side of lever 12 at points between pivot 13 and the presser-bar, and the action of lever l2 against the under side of lever 10 between said pivot and the presser-bar, enable the lifting pressure to come .close tothe axis of the presser-bar, without noticeable tendency to produce lateral pressure of the presser-bar within its bearings, or of sleeve 9b within its bearing at 3b, such as would occasion undue friction and cramping. Consequently wear of the bar and bearings is obviated.

The levers 12 and 10 constitute a compound lever, by which the effective leverage in clamping the nut is increased, and an easier action, with still further diminution in the lateral pressure of the presser-bar. As will be apparent, the lever 12 (herein a lever of the. second order) constitutes the primary lever-member of the compound lever arrangement, the lifting actuator acting thereagainst for the application of power to the compound lever, and the nut-locking lever 10 (herein a lever of the first order) constitutes the secondary lever-member of the compound lever arrangement. The illustrated combination of levers gives the best results in practice.

My invention obviates the disadvantages o f prior constructions of presser-lifting devices.

What is claimed as the invention is l. In presser-lifting devices comprising a presser, a presser-bar having a screwthreaded portion, a revolubfle nut fitting said portion, a carrier engaging with said nut for unison vertical movement therewith, and a lifting actuator, the combination therewith, of a compound-lever device mounted inconnection with said carrier and comprising a nut-locking secondary levermember and a primary lever-member respectively pivoted to said carrier the said lifting actuator acting to actuate said secondary lever-member for the purpose of locking the nut from turning, and to raise the presser and associated parts and control the descent thereof.

2. In presser-liftin devices comprising a presser, a presserar having a screwthreaded portion, a revoluble nut tting said portion, a carrier engaging with said nut for unison vertical movement therewith, and an actuating rocker, the combination therewith of a compound-lever device mounted in connection with said carrier and comprising a nut-locking secondary lever-member and a primary lever-member respectively 30 pivoted to said carrier, the said rocker acting to actuate said secondary lever-member for the purpose of locking the nut from turning, and to raise the presser and associated parts' and control the descent thereof.

3. In presser-lifting devices comprising a presser, a presser-bar having a screwthreaded portion, a nut fitting said portion, a carrier engaging with said nut for unison vertical movement therewith, and an actuating rocker-arm swinging vertically between its axis of oscillation and the presserbar, the combination therewith of a compound lever device mounted in connection with said carrier and comprising a nut-locking secondary lever-member having a power-arm extending away from the presser-bar, and a primary lever-member having an outstanding pivoted connection with said carrier and with which the rockerarm engages between said pivot and the presser-bar for the purpose of locking the nut from turning, and to raise the presser and associated parts and control the descent thereof.

In testimony whereof I aiix my signature 5f 

